Bill of materials and git-diff

Last year, I was assigned to a dry-dock campaign, and tasked with developing structural remediation scopes in an FPSO. Early on in the process, I made a decision to keep the content of work scope (SOW) separate from its associated bill of materials (BOM) list, imagining that it would some day be handy to concatenate for all scopes easily.

Using Typst, I was able to call the associated BOM as an immutable block of code within the SOW document like so:

#let qty = csv(scope.num + "-bom.csv")

#table(
  columns: 3,
  ..for (sl, description, quantity) in qty {
    (sl, description, quantity)
  }
)

With both SOW and BOM (in CSV) being plain text files meant I could track changes with git, of course.

Both these decisions, i.e., (a) separating BOM from SOW content, and (b) tracking changes with git, have served me well.

Recently, I was asked for a list of changes to the BOM between a previous revision and the latest.¹ Since BOM was version-controlled with git, I could just run these following commands and get the diffs between, say, RevB (tag) and the latest update (HEAD).

View commit history:

git log RevB..HEAD -- '*.csv'

List filenames only:

git diff --name-only RevB..HEAD -- '*.csv'

View impact (stats):

git diff --stat RevB..HEAD -- '*.csv'

View line changes:

git diff -w --word-diff=plain RevB..HEAD -- '*.csv'

I could then generate a nice output (post a little clean-up), like below, for the interested parties to review and take account of.

// Legend:
// - [-x-]: deletions
// - {+y+}: additions 

ST-163
1, PLT 10 THK (JIS G 3192 or equiv.), [-2-]{+4+} sq.m 
2, Coatings as per COMPANY spec. TGEN-S75-1001, [-2-]{+4+} sq.m